1. Field of the Invention
The invention relates to a machine for reproducing writing intended to personalize automated mail by reproducing with a fountain pen, for example, signatures, flourishes and even salutations.
The invention relates more particularly to a pantograph-type machine for reproducing writing and is directed to improving the pantograph control system.
2. Description of the Prior Art
Various pantograph-type machines for reproducing writing are known in the art. A system of this kind is generally considered to be better for this purpose than an X-Y plotter, which is relatively slow at reproducing irregular curves such as those encountered in handwriting and/or a signature.
In the field of machines of this type, French patent No. 78 08626 describes a two-branch pantograph in which each branch has two elements articulated end-to-end and joined together at an articulation near which is attached the writing device, which can be a fountain pen. The mechanism is fitted with feelers for following the edges of an endless flexible belt which constitutes a kind of control cam for executing signatures. The movement of the belt conditions the displacement of each feeler and consequently each branch of the pantograph.
In other systems known in the art, the endless tape is replaced by a wooden disk whose contour is shaped to control the movements of the two branches of the pantograph and consequently of the fountain pen.
The belt or the disk, or more generally the member constituting the control cam, is of course representative of a given signature. The production of a component of this kind is complicated and costly.
Moreover, it is difficult to envisage using a system of the above kind to reproduce anything other than a simple signature, for example a salutation. In particular, the salutation may need to change according to the nature of the letter and this may require a plurality of cams to be produced for the same signature.
The invention solves all the above problems by proposing a motorized pantograph.
The invention provides a machine for reproducing writing, in particular signatures, including a pantograph carrying a fountain pen or the like and having two branches with respective operating shafts coupled to respective electric rotational drive means, the machine further including control means for the drive means adapted to deliver electrical information representative of predetermined manuscript writing.
The pantograph can have two branches with two articulated members joined together by an articulation near which the fountain pen is attached. The two ends of the two branches are respectively provided with the operating shafts, which are driven by two electric motors. The motors are advantageously stepper motors with open-loop control. The motors can instead be DC motors with their position sensed by an optical encoder or the like or contactless motors controlled the same way.
Each motor is preferably coupled to a corresponding operating shaft of the pantograph by a speed-reducing mechanism. The speed-reducing mechanism can include a lead screw fixed to the shaft of the motor and a gear or toothed sector coupled to the operating shaft. Other speed reducers can be used instead, employing notched belts or gears, for example (this list is not comprehensive). The speed reducers might also be eliminated by using high-torque motors to drive each operating shaft directly.
The control means advantageously include a memory storing information representative of synchronized movements of the two motors. The information stored in this memory is read and decoded in a predetermined order and under the control of a clock to control the movement of the two motors and consequently of the fountain pen at the end of the pantograph. The memory therefore and advantageously replaces the cam system used previously. The memory can be a preprogrammed read-only memory containing information for reproducing a signature and an accompanying salutation, for example. The use of a readonly memory is advantageous in that it can be incorporated into a removable module that can easily be replaced by another similar module containing information representative of other predetermined writing, namely another signature and/or another salutation. The memory also contains information for commanding raising of the pantograph so that the fountain pen is not always in contact with the sheet of paper, should this be necessary for the required reproduction.
According to another advantageous feature of the invention the pantograph includes a lifting lever consisting of a plurality of articulated members controlled by an electric actuator such as an electric motor or an electromagnet and an associated cam. The cam actuates the lever, which is attached to the aforementioned two branches of the pantograph, preferably at the articulation between the two branches.
The invention will be better understood and other advantages of the invention will become more clearly apparent in the light of the following description of a machine in accordance with the invention for reproducing writing, which description is given by way of example only and with reference to the accompanying drawings.